Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.
A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.
Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.
Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.
This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.
This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.
After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add support of manipulation by attributes file.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Reported-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an error message for the case of failure of sync fs in
delayed_sync_fs() method.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add to hfs_btree_write() a return of -EIO on failure of b-tree node
searching. Also add logic ofor processing errors from hfs_btree_write()
in hfsplus_system_write_inode() with a message about b-tree writing
failure.
[akpm@linux-foundation.org: reduce scope of `err', print errno on error]
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use -ENOMEM return value instead of -EINVAL when kzalloc() fails.
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes hfsplus stop using the VFS '->write_super()' method along with
the 's_dirt' superblock flag, because they are on their way out.
The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblocks using the '->write_super()' call-back. But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.
Tested using fsstress from the LTP project.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This check is useless because we always have 'sb->s_fs_info' to be non-NULL.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Print correct function name in the debugging print of the
'hfsplus_sync_fs()' function.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... because it is used only in fs/hfsplus/super.c.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
generic_check_addressable can't deal with hfsplus's larger than page
size allocation blocks, so simply opencode the checks that we actually
need in hfsplus_fill_super.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Reported-by: Pavel Ivanov <paivanof@gmail.com>
Tested-by: Pavel Ivanov <paivanof@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 6596528e39 ("hfsplus: ensure bio requests are not smaller than
the hardware sectors") changed the pointers used for volume header
allocations but failed to free the correct pointers in the error path
path of hfsplus_fill_super() and hfsplus_read_wrapper.
The second hunk came from a separate patch by Pavel Ivanov.
Reported-by: Pavel Ivanov <paivanof@gmail.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently all bio requests are 512 bytes, which may fail for media
whose physical sector size is larger than this. Ensure these
requests are not smaller than the block device logical block size.
BugLink: http://bugs.launchpad.net/bugs/734883
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Implement error propagation through the callers of
hfsplus_ext_write_extent_locked().
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
hfs_find_init() may fail with ENOMEM, but there are places, where
the returned value is not checked. The consequences can be very
unpleasant, e.g. kfree uninitialized pointer and
inappropriate mutex unlocking.
The patch adds checks for errors in hfs_find_init().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Replace the hardcoded 2TB limit with a dynamic limit based on the block
size now that we have fixed the few overflows preventing operation
with large volumes.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
There is a misprint in resource deallocation code on error path in
hfsplus_fill_super(): the sbi->alloc_file inode is iput twice,
while the root inode in not iput at all.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently the error handling in hfsplus_fill_super is a mess, and can
lead to accessing fields in the superblock that haven't been even set
up yet. Fix this by making sure we do not set up sb->s_root until we
have the mount fully set up, and before that do proper step by step
unwinding instead of using hfsplus_put_super as a big hammer.
Reported-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus:
hfsplus: %L-to-%ll, macro correction, and remove unneeded braces
hfsplus: spaces/indentation clean-up
hfsplus: C99 comments clean-up
hfsplus: over 80 character lines clean-up
hfsplus: fix an artifact in ioctl flag checking
hfsplus: flush disk caches in sync and fsync
hfsplus: optimize fsync
hfsplus: split up inode flags
hfsplus: write up fsync for directories
hfsplus: simplify fsync
hfsplus: avoid useless work in hfsplus_sync_fs
hfsplus: make sure sync writes out all metadata
hfsplus: use raw bio access for partition tables
hfsplus: use raw bio access for the volume headers
hfsplus: always use hfsplus_sync_fs to write the volume header
hfsplus: silence a few debug printks
hfsplus: fix option parsing during remount
Fix up conflicts due to VFS changes in fs/hfsplus/{hfsplus_fs.h,unicode.c}
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Match coding style line length limitation where checkpatch.pl
reported over-80-character-line warnings.
Signed-off-by: Anton Salikhmetov <alexo@tuxera.com>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Flush the disk cache in fsync and sync to make sure data actually is
on disk on completion of these system calls. There is a nobarrier
mount option to disable this behaviour. It's slightly misnamed now
that barrier actually are gone, but it matches the name used by all
major filesystems.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Avoid doing unessecary work in fsync. Do nothing unless the inode
was marked dirty, and only write the various metadata inodes out if
they contain any dirty state from this inode. This is archived by
adding three new dirty bits to the hfsplus-specific inode which are
set in the correct places.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Split the flags field in the hfsplus inode into an extent_state
flag that is locked by the extent_lock, and a new flags field
that uses atomic bitops. The second will grow more flags in the
next patch.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
There is no reason to write out the metadata inodes or volume headers
during a non-blocking sync, as we are almost guaranteed to dirty them
again during the inode writeouts.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
hfsplus stores all metadata except for the volume headers in special
inodes. While these are marked hashed and periodically written out
by the flusher threads, we can't rely on that for sync. For the case
of a data integrity sync the VM has life-lock avoidance code that
avoids writing inodes again that are redirtied during the sync,
which is something that can happen easily for hfsplus. So make sure
we explicitly write out the metadata inodes at the beginning of
hfsplus_sync_fs.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
The hfsplus backup volume header is located two blocks from the end of
the device. In case of device sizes that are not 4k aligned this means
we can't access it using buffer_heads when using the default 4k block
size.
Switch to using raw bios to read/write all buffer headers. We were not
relying on any caching behaviour of the buffer heads anyway. Additionally
always read in the backup volume header during mount to verify that we
can actually read it.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Remove opencoded writing of the volume header in hfsplus_fill_super
and hfsplus_put_super and offload it to hfsplus_sync_fs. In the
put_super case this means we only write the superblock once instead
of twice.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Turn a few noisy debug printks that show up during xfstests into
complied out debug print statements.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
hfsplus only actually uses the force option during remount, but it uses
the full option parser with a fake superblock to do so. This means remount
will fail if any nls option is set (which happens frequently with older
mount tools), even if it is the same.
Fix this by adding a simpler version of the parser that only parses the force
option for remount.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
The flags in the HFS+-specific superlock do get modified during runtime,
use atomic bitops to make the modifications SMP safe.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Lock updates to the mutal fields in the volume header, and document the
locing in the hfsplus_sb_info structure.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
We never walk the list - the only reason for it is to make the resource fork
inodes appear hashed to the writeback code. Borrow a trick from JFS to do
that without needing a list head.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
We never look at it, nor change the next_alloc field in the superblock. So
don't bother caching it or writing it out in hfsplus_sync_fs.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Add a new hfsplus_system_write_inode for writing the special system inodes
and streamline the fastpath write_inode code.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Add a new hfsplus_system_read_inode for reading the special system inodes
and streamline the fastpath iget code.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
HFSPLUS_I doesn't return a pointer to the hfsplus-specific inode
information like all other FOO_I macros, but dereference the pointer in a way
that made it look like a direct struct derefence. This only works as long
as the HFSPLUS_I macro is used directly and prevents us from keepig a local
hfsplus_inode_info pointer. Fix the calling convention and introduce a local
hip variable in all functions that use it constantly.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
HFSPLUS_SB doesn't return a pointer to the hfsplus-specific superblock
information like all other FOO_SB macros, but dereference the pointer in a way
that made it look like a direct struct derefence. This only works as long
as the HFSPLUS_SB macro is used directly and prevents us from keepig a local
hfsplus_sb_info pointer. Fix the calling convention and introduce a local
sbi variable in all functions that use it constantly.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Except for ->put_super the BKL is now gone from HFS, which means it's
superflous there too as ->put_super is serialized by the VFS.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Use alloc_mutex to protect hfsplus_sync_fs against itself and concurrent
allocations, which allows to get rid of lock_super in hfsplus.
Note that most fields in the superblock still aren't protected against
concurrent allocations, that will follow later.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Use a new per-sb alloc_mutex instead of abusing i_mutex of the alloc_file
to protect block allocations. This gets rid of lockdep nesting warnings
and prepares for extending the scope of alloc_mutex.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
